U.S. patent application number 11/999000 was filed with the patent office on 2008-07-31 for crystalline potassium salt of lipoxin a4 analogs.
This patent application is currently assigned to Bayer Schering Pharma Aktiengesellschaft. Invention is credited to Klaus Bartel, Wolfgang Beckmann, Christian Dinter, Danja Grossbach, Tilo Haag, Michael Sander, Gabriele Winter.
Application Number | 20080182897 11/999000 |
Document ID | / |
Family ID | 39076610 |
Filed Date | 2008-07-31 |
United States Patent
Application |
20080182897 |
Kind Code |
A1 |
Haag; Tilo ; et al. |
July 31, 2008 |
Crystalline potassium salt of lipoxin A4 analogs
Abstract
This invention is directed to the crystalline potassium salt of
a lipoxin A.sub.4 analog of Formula (I): ##STR00001## processes for
preparing the crystalline potassium salts, methods for using them
to treat disease-states characterized by inflammation, and
pharmaceutical compositions comprising such crystalline potassium
salts.
Inventors: |
Haag; Tilo; (Berlin, DE)
; Grossbach; Danja; (Berlin, DE) ; Winter;
Gabriele; (Schonfliess, DE) ; Sander; Michael;
(Frechen, DE) ; Beckmann; Wolfgang; (Berlin,
DE) ; Bartel; Klaus; (Berlin, DE) ; Dinter;
Christian; (Berlin, DE) |
Correspondence
Address: |
JACQUELINE S LARSON
245 AVINGTON ROAD
ALAMEDA
CA
94502
US
|
Assignee: |
Bayer Schering Pharma
Aktiengesellschaft
Berlin
DE
|
Family ID: |
39076610 |
Appl. No.: |
11/999000 |
Filed: |
December 3, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60872830 |
Dec 4, 2006 |
|
|
|
Current U.S.
Class: |
514/532 ;
560/60 |
Current CPC
Class: |
A61P 29/00 20180101;
A61P 3/10 20180101; A61P 37/00 20180101; A61P 11/06 20180101; A61P
17/06 20180101; A61P 25/16 20180101; C07C 59/70 20130101; A61P 1/02
20180101; A61P 19/02 20180101; A61P 1/04 20180101; A61P 11/08
20180101; A61P 25/04 20180101; A61P 17/04 20180101; A61P 25/00
20180101; A61P 11/00 20180101; A61P 27/06 20180101; A61P 9/00
20180101; A61P 25/14 20180101; A61P 11/02 20180101; A61P 37/02
20180101; A61P 11/16 20180101; A61P 35/00 20180101; A61P 31/04
20180101; A61P 13/12 20180101; C07C 51/412 20130101; A61P 25/28
20180101; A61P 1/00 20180101; C07C 57/04 20130101; A61P 9/10
20180101; A61P 17/00 20180101; C07C 51/412 20130101; A61P 27/02
20180101; A61P 9/12 20180101 |
Class at
Publication: |
514/532 ;
560/60 |
International
Class: |
A61K 31/216 20060101
A61K031/216; C07C 69/734 20060101 C07C069/734; A61P 29/00 20060101
A61P029/00 |
Claims
1. A crystalline potassium salt of Formula (I): ##STR00006##
wherein: R.sup.1 is --O--, --S(O).sub.t-- (where t is 0, 1 or 2),
or a straight or branched alkylene chain; and R.sup.2 is aryl
(optionally substituted by one or more substituents selected from
alkyl, alkoxy, halo, haloalkyl and haloalkoxy) or aralkyl
(optionally substituted by one or more substituents selected from
alkyl, alkoxy, halo, haloalkyl and haloalkoxy); and wherein the
compound of Formula (I) is a single stereoisomer or any mixture of
stereoisomers.
2. The crystalline potassium salt according to claim 1 wherein
R.sup.1 is --O-- and R.sup.2 is phenyl optionally substituted by
one or more substituents selected from fluoro, chloro and iodo.
3. The crystalline potassium salt according to claim 2 having the
formula: ##STR00007## as a single stereoisomer or any mixture of
stereoisomers.
4. The crystalline potassium salt according to claim 3, wherein the
crystalline potassium salt is selected from: potassium
2-((2S,3R,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; potassium
2-((2R,3R,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; potassium
2-((2S,3S,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; potassium
2-((2R,3S,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; potassium
2-((2S,3R,4E,6E,10E,12R)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; potassium
2-((2R,3R,4E,6E,10E,12R)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; potassium
2-((2S,3S,4E,6E,10E,12R)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; and potassium
2-((2R,3S,4E,6E,10E,12R)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate.
5. The crystalline potassium salt according to claim 3, wherein the
crystalline potassium salt is potassium
2-((2S,3R,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate: ##STR00008##
6. The crystalline potassium salt according to claims 1 wherein the
crystalline potassium salt is in the form of an anhydrate.
7. The crystalline potassium salt according to claim 5 wherein the
crystalline potassium salt is in the form of an anhydrate
characterized by a X-ray powder diffraction pattern having a
characteristic peak at about d=26.7 .ANG..
8. The crystalline potassium salt according to claim 5 wherein the
crystalline potassium salt is in the form of an anhydrate
characterized by a X-ray powder diffraction pattern having a
characteristic peak at about d=26.7 .ANG. and about d=3.7
.ANG..
9. The crystalline potassium salt according to claim 1 wherein the
crystalline potassium salt forms a hydrate.
10. The crystalline potassium salt according to claim 1 wherein the
crystalline potassium salt is in the form of a monohydrate.
11. The crystalline potassium salt according to claim 5 wherein the
crystalline potassium salt is in the form of a monohydrate
characterized by a X-ray powder diffraction pattern having a
characteristic peak at about d=26.5 .ANG..
12. The crystalline potassium salt according to claim 5 wherein the
crystalline potassium salt is in the form of a monohydrate
characterized by a X-ray powder diffraction pattern having a
characteristic peak at about d=26.5 .ANG., about d=4.3 .ANG. and
about d=4.0 .ANG..
13. The crystalline potassium salt according to claim 1 wherein the
crystalline potassium salt is in the form of a dihydrate.
14. The crystalline potassium salt according to claim 5 wherein the
crystalline potassium salt is in the form of a dihydrate
characterized by a X-ray powder diffraction pattern having a
characteristic peak at about d=27.1 .ANG..
15. The crystalline potassium salt according to claim 5 wherein the
crystalline potassium salt is in the form of a dihydrate
characterized by a X-ray powder diffraction pattern having a
characteristic peak at about d=27.1 .ANG., about d=4.2 .ANG. and
about d=4.1 .ANG..
16. The crystalline potassium salt according to claim 1 wherein the
crystalline potassium salt is in the form of a dehydrated
hydrate.
17. The crystalline potassium salt according to claim 5 wherein the
crystalline potassium salt is in the form of a dehydrated hydrate
characterized by a X-ray powder diffraction pattern having a
characteristic peak between about d=27.1 .ANG. and about d=24.1
.ANG..
18. A method of synthesizing a crystalline potassium salt of
Formula (I) ##STR00009## wherein: R.sup.1 is --O--, --S(O).sub.t--
(where t is 0, 1 or 2), or a straight or branched alkylene chain;
and R.sup.2 is aryl (optionally substituted by one or more
substituents selected from alkyl, alkoxy, halo, haloalkyl and
haloalkoxy) or aralkyl (optionally substituted by one or more
substituents selected from alkyl, alkoxy, halo, haloalkyl and
haloalkoxy); the method comprising: 1) mixing a potassium base, in
a suitable solvent, together with the free acid corresponding to
the salt of Formula (I), in a suitable solvent; 2) optionally
cooling the resulting suspension; 3) isolating the resulting
crystals from the resulting suspension; 4) optionally washing the
isolated crystals with a suitable solvent; and 5) drying the
isolated crystals, to give the crystalline potassium salt (I); and
wherein the compound of Formula (I) is a single stereoisomer or any
mixture of stereoisomers.
19. The method according to claim 18 wherein the suitable solvent
for the potassium base comprises an organic solvent and water, and
wherein the suitable solvent for the free acid comprises an organic
solvent and water, and wherein the suitable solvent for washing the
isolated crystals compromises an organic solvent and water.
20. The method according to claim 18 wherein the drying step occurs
under conditions that correlate with the stability domain of the
monohydrate form or of the dihydrate form to give the monohydrate
form or the dehydrate form, respectively, of the potassium
salt.
21. A method of synthesizing a crystalline anhydrate of a potassium
salt according to claim 1 ##STR00010## wherein: R.sup.1 is --O--,
--S(O).sub.t-- (where t is 0, 1 or 2), or a straight or branched
alkylene chain; and R.sup.2 is aryl (optionally substituted by one
or more substituents selected from alkyl, alkoxy, halo, haloalkyl
and haloalkoxy) or aralkyl (optionally substituted by one or more
substituents selected from alkyl, alkoxy, halo, haloalkyl and
haloalkoxy); the method comprising: 1) digesting a hydrate or a
mixture of hydrates of a potassium salt of Formula (I) in a
suitable solvent; 2) optionally heating the resulting suspension;
3) isolating the resulting crystals; 4) optionally washing the
isolated crystals with a suitable solvent; and 5) drying the
isolated crystals, to give the crystalline anhydrate form of the
potassium salt(I); and wherein the compound of Formula (I) is a
single stereoisomer or any mixture of stereoisomers.
22. The method according to claim 21 wherein the suitable solvent
for the hydrate or the mixture of hydrates of the potassium salt
comprises an organic solvent and wherein the suitable solvent for
washing the isolated crystals compromises an organic solvent.
23. The method according to claim 21 wherein the drying step occurs
under conditions that correlate with the stability domain of the
anhydrate form.
24. A pharmaceutical composition comprising one or more
pharmaceutically acceptable excipients and a therapeutically
effective amount of a crystalline potassium salt of claim 1.
25. A method of treating a disease-state characterized by
inflammation in a mammal, the method comprising administering to
the mammal in need thereof a therapeutically effective amount of a
crystalline potassium salt of claim 1.
Description
[0001] This application claims the benefit of Provisional U.S.
application Ser. No. 60/872,830, filed Dec. 4, 2006, the entire
disclosure of which is incorporated herein by reference.
[0002] The invention relates to the crystalline potassium salts of
lipoxin A.sub.4 analogs, their use in treating a disease-state
characterized by inflammation, and pharmaceutical compositions
containing the crystalline potassium salts of the analogs and
processes for their preparation.
[0003] Lipoxins, together with leukotrienes, prostaglandins, and
thromboxanes, constitute a group of biologically active oxygenated
fatty acids collectively referred to as the eicosanoids.
Eicosanoids are all synthesized de novo from membrane phospholipid
via the arachidonic acid cascade of enzymes. Since their initial
discovery in 1984, it has become apparent that lipoxins, which are
a structurally unique class of eicosanoids, possess potent
anti-inflammatory properties that suggest they may have therapeutic
potential (Serhan, C. N., Prostaglandins (1997), Vol. 53, pp.
107-137; O'Meara, Y. M. et al., Kidney Int. (Suppl.) (1997), Vol.
58, pp. S56-S61; Brady, H. R. et al., Curr. Opin. Nephrol.
Hypertens. (1996), Vol. 5, pp. 20-27; and Serhan, C. N., Biochem.
Biophys. Acta. (1994), Vol. 1212, pp. 1-25). Of particular interest
is the ability of lipoxins to antagonize the pro-inflammatory
functions of leukotrienes in addition to other inflammatory agents
such as platelet activating factor, fMLP (formyl-Met-Leu-Phe)
peptide, immune complexes, and TNF.alpha.. Lipoxins are thus potent
anti-neutrophil agents which inhibit polymorphoneutrophil (PMN)
chemotaxis, homotypic aggregation, adhesion, migration across
endothelial and epithelial cells, margination/diapedesis and tissue
infiltration (Lee, T. H., et al., Clin. Sci. (1989), Vol. 77, pp.
195-203; Fiore, S., et al., Biochemistry (1995), Vol. 34, pp.
16678-16686; Papyianni, A., et al., J. Immunol. (1996), Vol. 56,
pp. 2264-2272; Hedqvist, P., et al., Acta. Physiol. Scand. (1989),
Vol. 137, pp. 157-572; Papyianni, A., et al., Kidney Intl. (1995),
Vol. 47, pp. 1295-1302). In addition, lipoxins are able to
down-regulate endothelial P-selectin expression and adhesiveness
for PMNs (Papyianni, A., et al., J. Immunol. (1996), Vol. 56, pp.
2264-2272), bronchial and vascular smooth muscle contraction,
mesangial cell contraction and adhesiveness (Dahlen, S. E., et al.,
Adv. Exp. Med. Biol. (1988), Vo. 229, pp. 107-130; Christie, P. E.,
et al., Am. Rev. Respir. Dis. (1992), Vol. 145, pp. 1281-1284;
Badr, K. F., et al., Proc. Natl. Acad. Sci. (1989), Vol. 86, pp.
3438-3442; and Brady, H. R., et al., Am. J. Physiol. (1990), Vol.
259, pp. F809-F815) and eosinophil chemotaxis and degranulation
(Soyombo, O., et al., Allergy (1994), Vol. 49, pp. 230-234).
[0004] This unique anti-inflammatory profile of lipoxins,
particularly lipoxin A.sub.4, has prompted interest in exploiting
their potential as therapeutics for the treatment of inflammatory
or autoimmune disorders and pulmonary and respiratory tract
inflammation. Such disorders and inflammations that exhibit a
pronounced inflammatory infiltrate are of particular interest and
include, but are not limited to, inflammatory bowel diseases such
as Crohn's disease, dermatologic diseases such as psoriasis,
rheumatoid arthritis, and respiratory disorders, such as
asthma.
[0005] As with other endogenous eicosanoids, naturally-occurring
lipoxins are unstable products that are rapidly metabolized and
inactivated (Serhan, C. N., Prostaglandins (1997), Vol. 53, pp.
107-137). This has limited the development of the lipoxin field of
research, particularly with respect to in vivo pharmacological
assessment of the anti-inflammatory profile of lipoxins. Several
U.S. patents have been issued directed to compounds having the
active site of lipoxin A.sub.4, but with a longer tissue half-life.
See, e.g., U.S. Pat. Nos. 5,441,951 and 5,648,512. These compounds
retain lipoxin A.sub.4 receptor binding activity and the potent in
vitro and in vivo anti-inflammatory properties of natural lipoxins
(Takano, T., et al., J. Clin. Invest. (1998), Vol. 101, pp.
819-826; Scalia, R., et al., Proc. Natl. Acad. Sci. (1997), Vol.
94, pp. 9967-9972; Takano, T., et al., J. Exp. Med. (1997), Vol.
185, pp. 1693-1704; Maddox, J. F., et al., J. Biol. Chem. (1997),
Vol. 272, pp. 6972-6978; Serhan, C. N., et al., Biochemistry
(1995), Vol. 34, pp. 14609-14615).
[0006] Lipoxin A.sub.4 analogs of interest to the invention are
disclosed in U.S. Pat. No. 6,831,186 and in U.S. Patent Application
Publication No. 2004/0162433.
[0007] It is recognized in the art that it is particularly
advantageous that a solid pharmaceutical substance is crystalline,
rather than amorphous. Typically during the formation of a
crystalline solid by crystallisation from a solution, a
purification of the crystalline product is obtained. A crystalline
solid state form can be very well characterized and usually shows a
higher stability in comparison to an amorphous phase. By using a
crystalline solid as drug substance or ingredient of a drug
product, a potential recrystallisation of the amorphous phase,
including the change of the characteristics of the drug substance
or drug product, is avoided. Accordingly, there exists a need for a
stable crystalline solid state form of the lipoxin A.sub.4 analogs
disclosed in U.S. Pat. No. 6,831,186 and in U.S. Patent Application
Publication No. 2004/0162433.
SUMMARY
[0008] This invention is directed to a potent, selective, and
metabolically and chemically stable crystalline potassium salt of a
lipoxin A.sub.4 analog and its use in treating disease-states
characterized by inflammation, such as inflammatory or autoimmune
disorders and pulmonary or respiratory tract inflammation in
mammals, particularly in humans.
[0009] Accordingly, in one aspect this invention is directed to a
crystalline potassium salt of a lipoxin A.sub.4 analog of Formula
(I):
##STR00002##
wherein: [0010] R.sup.1 is --O--, --S(O).sub.t-- (where t is 0, 1
or 2), or a straight or branched alkylene chain; and [0011] R.sup.2
is aryl (optionally substituted by one or more substituents
selected from alkyl, alkoxy, halo, haloalkyl and haloalkoxy) or
aralkyl (optionally substituted by one or more substituents
selected from alkyl, alkoxy, halo, haloalkyl and haloalkoxy); and
wherein the compound of Formula (I) is a single stereoisomer or any
mixtures of stereoisomers.
[0012] The present invention encompasses all of the crystalline
forms of the potassium salt of Formula (I).
[0013] The salt of the invention exhibits an excellent stability
under stress test conditions.
[0014] In another aspect, this invention is directed to a method of
preparing the crystalline potassium salt of Formula (I), the method
comprising i) mixing a potassium base, in a suitable solvent,
together with the free acid corresponding to the potassium salt of
Formula (I), in a suitable solvent; ii) optionally cooling the
resulting suspension; iii) isolating the resulting crystals from
the resulting suspension; iv) optionally washing the isolated
crystals with a suitable solvent; and v) drying the isolated
crystals, to give the crystalline potassium salt.
[0015] The method of the invention in one embodiment comprises the
preparation of a suitable solution of acid and base, namely the
addition of appropriate amounts of water to induce the formation of
crystals with a high crystallinity.
[0016] The method of the invention in one embodiment comprises the
controlled drying of the salt to a desired hydrate state, this
state being either dihydrate, monohydrate or the dehydrated
state.
[0017] The method of the invention in one embodiment is directed to
the preparation of the crystalline anhydrate form of the potassium
salt of Formula (I), the method comprising digestion of a hydrate
or mixture of hydrates of the potassium salt (I) in a suitable
solvent.
[0018] In a further aspect, this invention is directed to
pharmaceutical compositions comprising a therapeutically effective
amount of a crystalline potassium salt of Formula (I), as described
above, and one or more pharmaceutically acceptable excipients.
[0019] In another aspect, this invention is directed to the use of
a crystalline potassium salt of Formula (I), as described above,
for the manufacture of a medicament for treating a mammal having a
disease-state characterized by inflammation, such as for example an
inflammatory or autoimmune disorder or a pulmonary or respiratory
tract inflammation.
[0020] In another aspect, this invention is directed to methods of
treating a disease-state in a mammal, particularly a human,
characterized by inflammation, wherein the method comprises
administering to the mammal in need thereof a therapeutically
effective amount of a crystalline potassium salt of Formula (I) as
described above. The disease-state may be, for example, an
inflammatory or autoimmune disorder or a pulmonary or respiratory
tract inflammation.
A. DEFINITIONS
[0021] All of the references cited herein, including U.S. patents,
U.S. published patent applications and journal articles, are
incorporated in full by reference herein.
[0022] As used herein the singular forms "a", "an", and "the"
include plural referents unless the context clearly dictates
otherwise. For example, "a compound" refers to one or more of such
compounds, while "the enzyme" includes a particular enzyme as well
as other family members and equivalents thereof as known to those
skilled in the art.
[0023] All percentages herein are by volume, unless otherwise
indicated.
[0024] Furthermore, as used in the specification and appended
claims, unless specified to the contrary, the following terms have
the meaning indicated:
[0025] "Alkyl" refers to a straight or branched hydrocarbon chain
radical consisting solely of carbon and hydrogen atoms, containing
no unsaturation, having from one to eight carbon atoms, and which
is attached to the rest of the molecule by a single bond, e.g.,
methyl, ethyl, n-propyl, 1-methylethyl (isopropyl), n-butyl,
n-pentyl, 1,1-dimethylethyl (t-butyl), and the like.
[0026] "Alkylene chain" refers to a straight or branched divalent
hydrocarbon chain consisting solely of carbon and hydrogen,
containing no unsaturation and having from one to eight carbon
atoms, e.g., methylene, ethylene, propylene, n-butylene, and the
like.
[0027] "Alkoxy" refers to a radical of the formula --OR.sub.a where
R.sub.a is an alkyl radical as defined above.
[0028] "Aryl" refers to a phenyl or naphthyl radical. Unless stated
otherwise, the aryl radical may be optionally substituted by one or
more substituents selected from the group consisting of alkyl,
alkoy, halo, haloalkyl or haloalkoxy. Unless stated otherwise
specifically in the specification, it is understood that such
substitution can occur on any carbon of the aryl radical.
[0029] "Aralkyl" refers to a radical of the formula
--R.sub.aR.sub.b where R.sub.a is an alkyl radical as defined above
and R.sub.b is an aryl radical as defined above, e.g., benzyl and
the like. The aryl radical may be optionally substituted as
described above.
[0030] "Halo" refers to bromo, chloro, iodo or fluoro.
[0031] "Haloalkyl" refers to an alkyl radical, as defined above,
that is substituted by one or more halo radicals, as defined above,
e.g., trifluoromethyl, difluoromethyl, trichloromethyl,
2,2,2-trifluoroethyl, 1-fluoromethyl-2-fluoroethyl
(1,3-difluoroisopropyl), 3-bromo-2-fluoropropyl,
1-bromomethyl-2-bromoethyl (1,3-dibromoisopropyl), and the
like.
[0032] "Haloalkoxy" refers to a radical of the formula --OR.sub.c
where R.sub.c is an haloalkyl radical as defined above, e.g.,
trifluoromethoxy, difluoromethoxy, trichloromethoxy,
2,2,2-trifluoroethoxy, 1-fluoromethyl-2-fluoroethoxy,
3-bromo-2-fluoropropoxy, 1-bromomethyl-2-bromoethoxy, and the
like.
[0033] As used herein, compounds which are "commercially available"
may be obtained from standard chemical supply houses and other
commercial sources including, but not limited to, Acros Organics
(Pittsburgh Pa.), Aldrich Chemical (Milwaukee Wis., including Sigma
Chemical and Fluka), Apin Chemicals Ltd. (Milton Park UK), Avocado
Research (Lancashire U.K.), BDH Inc. (Toronto, Canada), Bionet
(Cornwall, U.K.) Chemservice Inc. (West Chester Pa.), Crescent
Chemical Co. (Hauppauge N.Y.), Eastman Organic Chemicals, Eastman
Kodak Company (Rochester N.Y.), Fisher Scientific Co. (Pittsburgh
Pa.), Fisons Chemicals (Leicestershire UK), Frontier Scientific
(Logan Utah), ICN Biomedicals, Inc. (Costa Mesa Calif.), Key
Organics (Cornwall U.K.), Lancaster Synthesis (Windham N.H.),
Maybridge Chemical Co. Ltd. (Cornwall U.K.), Parish Chemical Co.
(Orem Utah), Pfaltz & Bauer, Inc. (Waterbury Conn.),
Polyorganix (Houston Tex.), Pierce Chemical Co. (Rockford Ill.),
Riedel de Haen AG (Hannover, Germany), Spectrum Quality Product,
Inc. (New Brunswick, N.J.), TCI America (Portland Oreg.), Trans
World Chemicals, Inc. (Rockville Md.), and Wako Chemicals USA, Inc.
(Richmond Va.).
[0034] "Mammal" includes humans and domesticated animals, such as
cats, dogs, swine, cattle, sheep, goats, horses, rabbits, and the
like.
[0035] As used herein, "methods known to one of ordinary skill in
the art" may be identified though various reference books and
databases. Suitable reference books and treatises that detail the
synthesis of reactants useful in the preparation of compounds of
the present invention, or provide references to articles that
describe the preparation, include for example, "Synthetic Organic
Chemistry", John Wiley & Sons, Inc., New York; S. R. Sandler et
al., "Organic Functional Group Preparations," 2nd Ed., Academic
Press, New York, 1983; H. O. House, "Modern Synthetic Reactions",
2nd Ed., W. A. Benjamin, Inc. Menlo Park, Calif. 1972; T. L.
Gilchrist, "Heterocyclic Chemistry", 2nd Ed., John Wiley &
Sons, New York, 1992; J. March, "Advanced Organic Chemistry:
Reactions, Mechanisms and Structure", 4th Ed., Wiley-Interscience,
New York, 1992. Specific and analogous reactants may also be
identified through the indices of known chemicals prepared by the
Chemical Abstract Service of the American Chemical Society, which
are available in most public and university libraries, as well as
through on-line databases (the American Chemical Society,
Washington, D.C., www.acs.org may be contacted for more details).
Chemicals that are known but not commercially available in catalogs
may be prepared by custom chemical synthesis houses, where many of
the standard chemical supply houses (such as, for example, those
listed above) provide custom synthesis services.
[0036] "Optional" or "optionally" or "may be" means that the
subsequently described event or circumstance may or may not occur,
and that the description includes instances where said event or
circumstance occurs and instances in which it does not. For
example, "optionally substituted aryl" means that the aryl radical
may or may not be substituted and that the description includes
both substituted aryl radicals and aryl radicals having no
substitution.
[0037] "Polymorphs" refers to crystalline states of the same
chemical compounds of the invention. Wherein the "chemical
compounds" involves molecules or ions (salt) or a mixtures of a
molecule and an ion (salt). Solids exist in either amorphous or
crystalline forms. In the case of crystalline forms, molecules are
systematically positioned in 3-dimensional lattice sites. When a
compound crystallizes from a solution or slurry, it may crystallize
with different spatial lattice arrangements, a property referred to
as "polymorphism," with the different crystal forms individually
being referred to as a "polymorph". Different polymorphic forms of
a given substance may differ from each other with respect to one or
more physical properties, such as solubility and dissolution, true
density, crystal shape, compaction behavior, flow properties,
and/or solid state stability. In the case of a chemical substance
that exists in two (or more) polymorphic forms, the unstable forms
generally convert to the more thermodynamically stable forms at a
given temperature after a sufficient period of time. The
thermodynamically unstable form is referred to as the "metastable"
form. The transformation to a more stable form can be slow enough
as to assess the properties of the form even for drug substance
use. Thus, the metastable form may be found to exhibit sufficient
chemical and physical stability under normal storage conditions as
to permit its use in a commercial form. In this case, the
metastable form, although less stable, may exhibit properties
desirable over those of the stable form, such as enhanced
solubility or better oral bioavailability.
[0038] "Solvate" refers to an aggregate that comprises one or more
molecules of a compound of the invention with one or more molecules
of solvent or a non stoichiometric content of a solvent. The
solvent may be water, in which case the solvate is called a
hydrate. Alternatively, the solvent may be an organic solvent.
Thus, the potassium salts of lipoxin A.sub.4 analogs of Formula (I)
may exist as a hydrate, including a monohydrate, dihydrate,
hemihydrate, sesquihydrate, trihydrate, tetrahydrate, the
dehydrated hydrates with their non-stoichiometric water content,
and the like, as well as the corresponding solvated forms. The
potassium salts of Formula (I) may be true solvates, while in other
cases the salts may merely retain adventitious water or be a
mixture of water plus some adventitious solvent.
[0039] See, e.g., Byrn, S et al. "Solid State Chemistry of Drugs",
SSCI (1999), for a discussion of polymorphs and solvates, their
characterization and properties, and relevance for drug substances
and drug products; and Stahl, P and Wermuth, C "Handbook of
Pharmaceutical Salts", Wiley (2002), for a discussion of salts,
their preparation and properties.
[0040] As used herein, "suitable conditions" for carrying out a
synthetic step are explicitly provided herein or may be discerned
by reference to publications directed to methods used in synthetic
organic chemistry. The reference books and treatises set forth
above that detail the synthesis of reactants useful in the
preparation of compounds of the present invention, will also
provide suitable conditions for carrying out a synthetic step
according to the present invention.
[0041] "Suitable solvent" refers to any solvent that is compatible
with the components of the reaction and the reaction conditions.
The term encompasses one solvent or a mixture of solvents and
includes, but is not limited to organic solvents and water.
Suitable solvents are known to those of skill in the art or may be
discerned by reference to publications directed to methods used in
synthetic organic chemistry.
[0042] "Therapeutically effective amount" refers to that amount of
a potassium salt of the invention which, when administered to a
mammal, particularly a human, in need thereof, is sufficient to
effect treatment, as defined below, for a disease-state
characterized by inflammation. The amount of a potassium salt of
the invention which constitutes a "therapeutically effective
amount" will vary depending on the salt, its solvated form, the
disease-state to be treated and its severity, the age of the mammal
to be treated, and the like, but can be determined routinely by one
of ordinary skill in the art.
[0043] "Treating" or "treatment" as used herein covers the
treatment of a disease-state characterized by inflammation in a
mammal, preferably a human, such as for example an inflammatory or
autoimmune disorder or a pulmonary or respiratory tract
inflammation, and includes:
[0044] (i) preventing the disorder or inflammation from occurring
in a mammal, in particular, when such mammal is predisposed to the
disorder but has not yet been diagnosed as having it;
[0045] (ii) inhibiting the disorder or inflammation, i.e.,
arresting its development; or
[0046] (iii) relieving the disorder or inflammation, i.e., causing
regression of the disorder or inflammation.
[0047] The potassium salts of Formula (I) have three asymmetric
centers, which give rise to enantiomers, diastereomers, and other
stereoisomeric forms that may be defined, in terms of absolute
stereochemistry, as (R)- or (S)- or as (D)- or (L)-. The present
invention is meant to include all such possible isomers, as well as
their racemic and optically pure forms. Optically active (+) and
(-), (R)- and (S)-, or (D)- and (L)-isomers may be prepared using
chiral synthons or chiral reagents, or resolved using conventional
techniques, such as HPLC using a chiral column. The compounds
described herein contain olefinic double bonds or other centers of
geometric asymmetry and, unless specified otherwise, it is intended
that the compounds include both E and Z geometric isomers.
Likewise, all tautomeric forms are also intended to be
included.
[0048] A "stereoisomer" refers to a compound made up of the same
atoms bonded by the same bonds but having different
three-dimensional structures, which are not interchangeable. The
present invention contemplates various stereoisomers and mixtures
thereof and includes "enantiomers", which refers to two
stereoisomers whose molecules are nonsuperimposeable mirror images
of one another.
B. CRYSTALLINE POTASSIUM SALTS OF THE INVENTION
[0049] It is known that the formation of salts can dramatically
increase the stability of a pharmaceutical agent with respect to
its free acid and that the stability of salts differ between
different salt-forming agents. It is also known that crystalline
salt forms can be more stable than amorphous salt forms.
[0050] Accordingly, investigations were conducted with the goal of
finding a suitable stable crystalline salt of the acid of Formula
(II):
##STR00003##
wherein: [0051] R.sup.1 is --O--, --S(O).sub.t-- (where t is 0, 1
or 2) or a straight or branched alkylene chain; and [0052] R.sup.2
is aryl (optionally substituted by one or more substituents
selected from the group consisting of alkyl, alkoxy, halo,
haloalkyl and haloalkoxy) or aralkyl (optionally substituted by one
or more substituents selected from the group consisting of alkyl,
alkoxy, halo, haloalkyl and haloalkoxy); and wherein the acid of
Formula (II) is a single stereoisomer or any mixtures of
stereoisomers.
[0053] Through salt screening assays using a variety of organic and
inorganic cations, it was very surprisingly discovered that the
crystalline potassium salt of the acid (IIa)
##STR00004##
was substantially more stable than every other salt prepared and
was also more stable than acid (IIa) itself.
[0054] In one embodiment, the invention is directed to a
crystalline potassium salt of Formula (I) as disclosed and defined
in the Summary.
[0055] In another embodiment, the invention is directed to a
crystalline potassium salt of Formula (I) where R.sup.1 is --O--,
and R.sup.2 is phenyl optionally substituted by one or more
substituents selected from fluoro, chloro and iodo.
[0056] In a further embodiment, the compound of the invention is a
crystalline potassium salt of Formula (I) where R.sup.1 is --O--,
and R.sup.2 is 4-fluorophenyl.
[0057] In another embodiment, the compound of the invention is
selected from the following: [0058] potassium
2-((2S,3R,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; [0059] potassium
2-((2R,3R,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; [0060] potassium
2-((2S,3S,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; [0061] potassium
2-((2R,3S,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; [0062] potassium
2-((2S,3R,4E,6E,10E,12R)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; [0063] potassium
2-((2R,3R,4E,6E,10E,12R)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; [0064] potassium
2-((2S,3S,4E,6E,10E,12R)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate; and [0065] potassium
2-((2R,3S,4E,6E,10E,12R)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrideca-4,-
6,10-trien-8-ynyloxy)acetate.
[0066] In another aspect, the present invention is directed to a
crystalline potassium salt wherein the crystalline potassium salt
is potassium
2-((2S,3R,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxy-
trideca-4,6,10-trien-8-ynyloxy)acetate (Ia):
##STR00005##
C. SALT SCREENING
[0067] The following describes the salt screening assays in more
detail:
[0068] Materials:
[0069] Many inorganic cations were investigated to determine their
ability to form a stable crystalline salt of the acid (IIa),
including potassium, sodium, calcium, aluminium, magnesium,
lithium, and zinc.
[0070] Several organic amines were investigated, including
N-methylglucamine, diethanolamine, ethylenediamine, choline,
lysine, and arginine.
[0071] In addition to the foregoing, it was investigated to form a
mixed salt of the acid of Formula (IIa) with polyvalent inorganic
cations and organic acids.
[0072] Test Parameters:
[0073] In general, the salt screening assay included the
variability of the following different test parameters:
[0074] i) Type of cation-compound utilized (e.g., as carbonates,
hydroxides, methylates, ethylates).
[0075] ii) Type of solvent utilized.
[0076] iii) Specific addition or exclusion of water (to assist the
formation of hydrates or anhydrates).
[0077] iv) Type of crystallization utilized (cooling
crystallization, antisolvent crystallization, or evaporation
crystallization, and combinations thereof).
[0078] v) Type of screening (manual screening as well as high
throughput screening).
[0079] Results:
[0080] Surprisingly, it was discovered that only in the case of
using potassium compounds as the base was the formation of a
suspension and the isolation of a crystalline salt of the acid
(IIa) possible. The experiments with the other cations yielded
solutions without a solid phase, with oily phases, or as amorphous
solids. The formation of mixed salts failed, as well. Also, high
throughput-screening yielded no further crystalline salts of the
acid (IIa).
D. SOLID STATE FORMS OF THE POTASSIUM SALT OF FORMULA (Ia)
[0081] The crystalline potassium salt of Formula (Ia) forms three
well-defined crystalline forms: an anhydrate and two hydrates. In
addition, two dehydrated hydrate forms (dehydrated form I and
dehydrated form II) were obtained, and an amorphous phase was
detected in certain studies. No solvates were detected. The present
invention encompasses all crystalline forms of the potassium salts
of Formulas (I) and (Ia).
[0082] The different solid state forms of the potassium salt (Ia)
can be differentiated by the peak positions of the reflections in
the X-ray powder diffraction (XRPD) pattern. The strongest
reflections of anhydrate, monohydrate and dihydrate of crystalline
potassium salt (Ia) are given below in Table 1.
TABLE-US-00001 TABLE 1 X-ray powder diffraction data of the
anhydrate, monohydrate and dihydrate-d-values of the strongest
reflections, 2.THETA.-values (germanium-monochromatized
CuK.alpha..sub.1-radiation) anhydrate monohydrate dihydrate d
(.ANG.) d (.ANG.) d (.ANG.) 26.68 26.47 27.09 13.39 13.27 13.49
7.24 8.44 8.49 4.30 5.78 5.38 4.25 5.32 4.33 4.10 4.32 4.16 3.99
4.07 4.12 3.87 4.03 4.06 3.69 3.98 4.00 3.11 3.90 3.70 3.81 3.66
3.62 3.42 3.60 3.29 3.20 3.24
[0083] The anhydrate form of the crystalline potassium salt of
Formula (Ia) exhibits characteristic peaks at about d=26.7 .ANG.
and at about d=3.7 .ANG..
[0084] The monohydrate form of the crystalline potassium salt of
Formula (Ia) exhibits characteristic peaks at about d=26.5 .ANG.,
at about d=4.3 .ANG. and at about d=4.0 .ANG., while the dihydrate
form of the crystalline potassium salt of Formula (Ia) exhibits
characteristic peaks at about d=27.1 .ANG., at about d=4.2 .ANG.
and at about d=4.1 .ANG..
[0085] The XRPD patterns of the dehydrated form I and dehydrated
form II of the crystalline potassium salt of Formula (Ia) show that
the peak positions for both dehydrated forms vary slightly from
batch to batch due to the varying solvent residues. Therefore, no
exact d-values, 2.THETA.-values and relative intensities, which are
characteristic for both forms, can be given. However, they exhibit
characteristic peaks between about d=24.6 .ANG. and about d=27.1
.ANG..
[0086] One of ordinary skill in the art will appreciate that an
X-ray diffraction pattern may be obtained with a measurement error
that is dependent upon the measurement conditions employed. In
particular, it is generally known that intensities in an X-ray
diffraction pattern may fluctuate depending upon crystal habitus of
the material and measurement conditions employed. It is further
understood that relative intensities may also vary depending upon
experimental conditions and, accordingly, the exact order of
intensity should not be taken into account. Additionally, a
measurement error of diffraction angle Theta for a conventional
X-ray diffraction pattern at a given temperature is typically about
.+-.0.1.degree., and such degree of measurement error should be
taken into account as pertaining to the aforementioned diffraction
angles. Consequently, the term "about" when used herein in
reference to X-ray powder diffraction patterns means that the
crystal forms of the instant invention are not limited to the
crystal forms that provide X-ray diffraction patterns completely
identical to the X-ray diffraction patterns depicted in the
accompanying Figure disclosed herein. Any crystal form that
provides X-ray diffraction patterns that is substantially identical
as to those disclosed in the accompanying Figure falls within the
scope of the present invention. The ability to ascertain whether
the polymorphic forms of a compound are the same albeit the X-ray
diffraction patterns are not completely identical is within the
purview of one of ordinary skill in the art.
[0087] IR-spectroscopy of the hydrates of the potassium salt (Ia)
showed that they have characteristic IR bands at 1214 cm.sup.-1 and
1127 cm.sup.-1.
[0088] The water content of the crystalline potassium salt (Ia)
determines its solid state form (anhydrate, monohydrate, dihydrate,
dehydrated form I, or dehydrated form II). The actual water content
of the salt is determined by the ambient relative humidity and
temperature.
[0089] The transformation of the monohydrate and the dihydrate as
well as the dehydrated form II into each other is reversible. The
anhydrate is transformed into the dihydrate via the monohydrate.
This transformation is not reversible. The dihydrate is transformed
by dehydration into the dehydrated form II. The dehydrated form I
is transformed into the monohydrate and dihydrate as well. No
transformation of monohydrate or dihydrate form into the dehydrated
form I was observed.
[0090] The transformation of the monohydrate to the dihydrate form
and vice versa occurs quickly and is well defined at 25.degree. C.
and at 40.degree. C. This was shown by dynamic vapor sorption
investigations. For example, during pre-drying of the monohydrate
at 25.degree. C. and 0% relative humidity, 4.0% water is released
from the monohydrate. This results in the formation of dehydrated
form II. Between 20% and 40% relative humidity, one mole of water
is absorbed, resulting in the formation of the monohydrate. The
monohydrate is stable up to approximately 50% relative humidity and
then is transformed into the dihydrate by absorption of a second
mole of water between 50% and 60% relative humidity. The dihydrate
is the stable form up to 98% relative humidity at 25.degree. C.
During the desorption cycle between 40% and 50% relative humidity,
the transformation into the monohydrate takes place. The formed
monohydrate is existent up to 10% relative humidity. Between 0% and
10% relative humidity the dehydration of the monohydrate to the
dehydrated form II occurs. The corresponding sorption isotherm is
given in FIG. 1. No significant differences between the two cycles
were observed.
[0091] The hygroscopicity with respect to the transformation of the
monohydrate and dihydrate was re-investigated between 45% and 55%
relative humidity using smaller steps for the relative humidity.
This investigation shows that the equilibrium between the two
hydrates at 25.degree. C. is between 48% and 50% relative humidity.
At 40.degree. C. the reversible transformation between the
monohydrate and the dihydrate is between 57% and 59% relative
humidity, approximately 10% higher than at 25.degree. C. A more
detailed investigation at 40.degree. C. of the desorption range of
the monohydrate between 0% and 10% relative humidity showed that
the desorption takes place between 2% and 3% relative humidity.
[0092] Also, the transformation of the anhydrate form of the
potassium salt (Ia) to the hydrate form was shown by dynamic vapor
sorption investigations at 25.degree. C. Up to 40% relative
humidity the anhydrate was stable. Between 40% and 60% relative
humidity approximately two moles of water are absorbed, resulting
in the formation of the dihydrate.
[0093] Data collection for the XRPD was carried out in transmission
mode using germanium-monochromatized CuK.alpha..sub.1-radiation
(.lamda.=1.5406 .ANG.) at room temperature (between 20.degree. C.
and 25.degree. C.). The X-ray tube with copper anode was operated
by 40 kV and 30 mA. The 2.THETA. scans were performed using the
small linear position sensitive detector with an angular resolution
of 0.08.degree. between 3.degree..ltoreq.2.THETA..ltoreq.35.degree.
and 2.degree..ltoreq.2.THETA..ltoreq.35.degree. (stepwidth
0.5.degree.) or 7.degree..ltoreq.2.THETA..ltoreq.35.degree.
(stepwidth 0.5.degree.) if the wellplate was used. The samples were
enclosed between two polyacetate films held together by
double-sided adhesive tape or between two aluminum foils to avoid
the influence of the humidity during measurement. Data acquisition
and evaluation were performed using the STOE WinX.sup.pow software
package.
[0094] The IR spectra were recorded using diffuse reflection
technique. The samples were diluted with potassium bromide in a
ratio 1:100.
[0095] Data collection for the hygroscopicity studies was carried
out in an automated water sorption analyzer. Approximately 20 mg of
the investigated solid state form of the crystalline potassium salt
(Ia) was exposed to a continuous flow of nitrogen with
predetermined and constant relative humidity. The rate of sweep gas
was set at 200 cm.sup.3/min. For a basic assay, two full cycles
(sorption/desorption) were measured at 25.degree. C. The
measurement was started at 0% relative humidity in order to remove
surface water. Once the constant mass was achieved, the next
humidity was automatically set. The water sorption/desorption was
investigated in steps of 10% between 0% and 90% relative humidity
under the criteria for initiation of the first step as set forth
herein. Additionally, the sorption at about 98% relative humidity
was investigated. Data was acquired using the DVSWin software. In
addition, investigations at 40.degree. C. were carried out and, for
more detailed evaluation of the monohydrate/dihydrate equilibrium,
the steps in the relevant regions were shortened (each step equals
1% relative humidity).
E. CHEMICAL STABILITY OF SOLID STATE FORMS OF THE POTASSIUM SALT
(Ia)
[0096] The chemical stability of the anhydrate and the monohydrate
of the potassium salt of Formula (Ia) of the invention as well as
the dehydrated form I of the potassium salt (Ia) of the invention
were assessed by comparing the stability under stress at 40.degree.
C./75% rH over a period of 4 weeks. The result is shown in the
following Table 2.
TABLE-US-00002 TABLE 2 K-salt, K-salt, Anhydrate*; K-salt,
dehydrated 40.degree. C./ Monohydrate**; form I; 75% RH 40.degree.
C./75% RH 40.degree. C./75% RH weeks HPLC- 99.6 99.7 97.8 0 purity
[%] 99.7 99.6 97.1 2 99.7 99.7 95.3 4 *Started with the anhydrate
during the test, it was most likely the dihydrate form of the
potassium salt (Ia) at the end of the test **Started with the
monohydrate during the test, it was most likely the dihydrate form
of the potassium salt (Ia) at the end of the test
[0097] All three forms of the potassium salt (Ia) are sufficiently
stable; however, the anhydrate and the monohydrate of the potassium
salt (Ia) show no sign of degradation.
F. PREPARATION OF THE POTASSIUM SALTS OF FORMULAS (I) AND (Ia)
[0098] Compounds of Formula (II), i.e. the acid, are described in
detail in U.S. Pat. No. 6,831,186 and in U.S. Patent Application
Publication No. 2004/0162433, the pertinent disclosures of which
are incorporated in full herein by reference.
[0099] The method of preparing the crystalline potassium salt is
exemplified by using the salt of Formula (Ia) but can be used to
prepare crystalline potassium salts of other compounds of Formula
(I). In general, the method of preparing the crystalline potassium
salt (Ia) is based on the neutralization of the acid (IIa) by
treatment with a base. The resulting mixture forms a suspension,
which is then optionally cooled. The crystals are isolated from
suspension and dried to yield the desired hydrate form of the
crystalline potassium salt (Ia).
[0100] More particularly, the acid (IIa) is dissolved in a suitable
solvent, such as e.g. ethanol. Then a potassium base, such as
potassium methylate or potassium hydroxide for example, is
dissolved in a suitable solvent, such as e.g. ethanol. The solution
of the potassium base is added to the solution of the acid (IIa) or
vice versa.
[0101] The dosage of the potassium base to the solution of the acid
(III) is controlled by pH-measurement of the resulting mixture by
methods known in the art, such as via wet pH-indicator strips. In
one embodiment, the addition of the potassium base solution
generally is stopped when a pH of 6 to 15 is reached, normally when
a pH of 7 to 14 is reached and, in one presently preferred
embodiment, when a pH of 8 to 13 is reached.
[0102] The dehydrated form I of the potassium salt (Ia) is obtained
by excluding water in the reaction mixture. For example, this can
be achieved by using water-free solvents and by adding potassium
methylate to form the salt.
[0103] In addition, the dehydrated form I of the potassium salt
(Ia) can be obtained by suspending the monohydrate form of the
crystalline potassium salt (Ia) in organic solvents, such as for
example acetonitrile. No direct transformation of the monohydrate
form or the dihydrate form to the dehydrated form I by drying or
thermal treatment is observed.
[0104] To avoid the formation of the presently less desired
dehydrated hydrate form (I) of the potassium salt (Ia) during the
crystallization step, the solvent of the crystallization contains
at least some water. Generally, the final reaction mixture contains
at least about 0.01% water, normally about 0.5% to about 99.9%
water and, in one presently preferred embodiment, about 1% to about
30% water. Thus, for example, in one embodiment, the acid
(IIa)-solvent solution will contain at least some water. Generally,
the acid (IIa)-solvent solution contains at least about 0.01%
water, normally about 0.5% to about 99.9% water and, in one
presently preferred embodiment, about 1% to about 30% water.
Likewise, in one embodiment, the potassium base-solvent solution
will contain at least some water. Generally, the potassium
base-solvent solution contains at least about 0.01% water, normally
about 0.5% to about 99.9% water and, in one presently preferred
embodiment, about 1% to about 30% water. The resulting reaction
mixture will contain at least some water. The resulting mixture
forms a suspension that is optionally cooled prior to solid/liquid
isolation and an optional washing step with a suitable solvent.
Generally, the washing solvent contains at least about 0.01% water,
normally about 0.5% to about 99.9% water and, in one presently
preferred embodiment, about 1% to about 30% water. Then follows the
drying step.
[0105] The drying procedure of the isolated crystals defines the
hydrate form (monohydrate or dihydrate or dehydrated hydrate) of
the crystalline potassium salt prepared and thus should be well
controlled when one wishes to obtain the desired mono- or dihydrate
of the potassium salt (Ia). Also, the drying procedure avoids the
formation of the less desired dehydrated form (II) of the potassium
salt (Ia, which is obtained by overdrying of the product. The
optimization of this process is described in section G below.
[0106] The dehydrated form II of the potassium salt (Ia) can also
be formed by the dehydration of the hydrates by thermal treatment
(normally at a temperature below 100.degree. C.) or by storage at
0% relative humidity. The dehydration of the dihydrate via the
monohydrate results in the dehydrated form II.
[0107] In general, the method of preparing the anhydrate form of
the potassium salt (Ia) is based on the digestion of the hydrate
form of the potassium salt in a suitable solvent at higher
temperatures for a period of time. The crystals are isolated from
suspension and then dried to yield the anhydrate form of the
potassium salt (Ia).
[0108] More particularly, the hydrate of the potassium salt (Ia) is
digested in a suitable solvent, such as e.g. 1,4-dioxane. The
suspension is stirred and heated up to nearly the boiling point of
the solvent for generally about 0.1 to about 10 hours, normally
about 1 to about 8 hours, and preferably about 2 to about 6 hours.
Then the suspension is cooled down and the crystals are isolated
and optionally washed with a suitable solvent, such as e.g.
1,4-dioxane, after which the crystals are dried to yield the
anhydrate form of the potassium salt (Ia).
G. OPTIMIZATION OF THE DRYING PROCESS OF THE POTASSIUM SALT OF
FORMULA (Ia)
[0109] The formation of the potassium salt (Ia) in a preferred
crystalline hydrate form was optimized by varying the drying
conditions.
[0110] It was found by XRPD analysis of the wet filtercake that the
dihydrate form of the potassium salt is formed in the
crystallization step. During the drying process the filtercake
(that is, the dihydrate form of the potassium salt) loses its
moisture. But as the dihydrate form of the potassium salt loses its
water and transforms into the monohydrate form, the monohydrate
form can subsequently continue to transform to the less desirable
dehydrated form II.
[0111] As is evident from the DVS data, which shows the
dehydrate-monohydrate transition to be fast, a conventional drying
process, e.g. via a vacuum drying chamber, will not yield the
dihydrate. There is also the potential danger of overdrying of the
monohydrate to the dehydrated form II.
[0112] Thus, the drying process was optimized to yield either the
dihydrate or the monohydrate and to safely avoid overdrying to the
dehydrated form II.
[0113] The optimized drying process uses a very well-conditioned
and controlled sweep gas flow. Through the specific control and
setup of relative humidity of the sweep gas (such as, e.g.,
N.sub.2) and of the pressure and the temperature inside the dryer,
the drying step was carried out under conditions of temperature and
humidity that correlate with the stability domain of the desired
hydrate form. Following this process, the specific hydrate forms of
the potassium salt (Ia) could be obtained.
[0114] Also, investigations revealed that the use of a sweep gas is
useful in guaranteeing a sufficient drying time and in avoiding the
condensation of liquid in the dryer. In addition to the sweep gas
mentioned above, any appropriate sweep gas may be used in the
present invention, which gases are known to those of skill in the
art or can be determined without undue experimentation.
[0115] In addition to the use of a vacuum drying chamber, any
drying method or apparatus may be used in the process of the
present invention to dry the potassium salts of Formulas (I) and
(Ia), including but not limited to a mixing dryer (e.g., paddle
dryer or cone dryer), a contact dryer, a convection dryer, a
radiation dryer and the like, as are known to or may be identified
by those skilled in the art.
H. UTILITY OF THE CRYSTALLINE POTASSIUM SALTS OF THE INVENTION
[0116] The crystalline potassium salt of Formula (I) has biological
activity similar to that of natural lipoxin A.sub.4, but with an
enhanced resistance to chemical and metabolic degradation.
Accordingly, the crystalline potassium salt of Formula (I) is
useful in treating inflammatory or autoimmune disorders in mammals,
particularly in humans. In particular, a crystalline potassium salt
of Formula (I) is useful in inhibiting acute or chronic
inflammation or an inflammatory or autoimmune response that is
mediated by neutrophils, eosinophils, T lymphocytes, NK cells or
other immune cells that contribute to the pathogenesis of
inflammatory, immune or autoimmune diseases. The crystalline
potassium salt of Formula (I) is also useful in the treatment of
proliferative disorders including, but not limited to, those
associated with derangements in the inflammatory or immune
response, such as cancer. The crystalline potassium salt of Formula
(I) is also useful as an inhibitor of angiogenic responses in the
pathogenesis of cancer.
[0117] Accordingly, the crystalline potassium salt of Formula (I)
can be used to treat the following inflammatory or autoimmune
disorders in mammals, particularly in humans: anaphylactic
reactions, allergic reactions, allergic contact dermatitis,
allergic rhinitis, chemical and non-specific irritant contact
dermatitis, urticaria, atopic dermatitis, psoriasis, fistulas
associated with Crohn's disease, pouchitis, septic or endotoxic
shock, hemorrhagic shock, shock-like syndromes, capillary leak
syndromes induced by immunotherapy of cancer, acute respiratory
distress syndrome, traumatic shock, immune- and pathogen-induced
pneumonias, immune complex-mediated pulmonary injury and chronic
obstructive pulmonary disease, inflammatory bowel diseases
(including ulcerative colitis, Crohn's disease and post-surgical
trauma), gastrointestinal ulcers, diseases associated with
ischemia-reperfusion injury (including acute myocardial ischemia
and infarction, acute renal failure, ischemic bowel disease and
acute hemorrhagic or ischemic stroke), immune-complex-mediated
glomerulonephritis, autoimmune diseases (including
insulin-dependent diabetes mellitus, multiple sclerosis, rheumatoid
arthritis, osteoarthritis and systemic lupus erythematosus), acute
and chronic organ transplant rejection, transplant arteriosclerosis
and fibrosis, cardiovascular disorders (including hypertension,
atherosclerosis, aneurysm, critical leg ischemia, peripheral
arterial occlusive disease and Reynaud's syndrome), complications
of diabetes (including diabetic nephropathy, neuropathy and
retinopathy), ocular disorders (including macular degeneration and
glaucoma), neurodegenerative disorders (including delayed
neurodegeneration in stroke, Alzheimer's disease, Parkinson's
disease, encephalitis and HIV dementia), inflammatory and
neuropathic pain including arthritic pain, periodontal disease
including gingivitis, ear infections, migraine, benign prostatic
hyperplasia, cancers including, but not limited to, leukemias and
lymphomas, prostate cancer, breast cancer, lung cancer, malignant
melanoma, renal carcinoma, head and neck tumors and colorectal
cancer.
[0118] The crystalline potassium salt of Formula (I) is also useful
in treating folliculitis induced by inhibitors of epidermal growth
factor (EGF) or epidermal growth factor receptor (EGFR) kinase used
in the treatment of solid tumors. Clinical trials have revealed
folliculitis (inflammation of the hair follicle manifested by
severe acne-like skin rash on the face, chest and upper back) as a
major dose-limiting side effect of such treatments. Such
folliculitis is associated with an infiltration of neutrophils,
suggesting products secreted by activated neutrophils to be the
cause of the inflammation. The crystalline potassium salt of
Formula (I) inhibits neutrophil- or eosinophil-mediated
inflammation, and is therefore useful in treating such
folliculitis, thereby improving the quality of life of the treated
cancer patients but also allowing for the increase of the dosage of
the EGF inhibitor or EGFR kinase inhibitor or the extension of the
duration of the treatment, resulting in improved efficacy of the
desired inhibitor.
[0119] The crystalline potassium salt of Formula (I) is also useful
in the treatment of pulmonary and respiratory inflammation,
including, but not limited to, asthma, chronic bronchitis,
bronchiolitis, bronchiolitis obliterans (including such with
organizing pneumonia), allergic inflammation of the respiratory
tract (including rhinitis and sinusitis), eosinophilic granuloma,
pneumonias, pulmonary fibroses, pulmonary manifestations of
connective tissue diseases, acute or chronic lung injury, chronic
obstructive pulmonary diseases, adult respiratory distress
syndrome, and other non-infectious inflammatory disorders of the
lung characterized by eosinophil infiltration. For example, the
crystalline potassium salt of Formula (I) is useful in the
inhibition of: eosinophil-mediated inflammation of the lung or
tissues; neutrophil-mediated inflammation of the lung;
lymphocyte-mediated inflammation of the lung; cytokine and
chemokine production, including interleukin-5, interleukin-13 and
eotaxin; lipid mediator generation, including prostaglandin E.sub.2
and cysteinyl leukotrienes; airway hyper-responsiveness; and airway
and vascular inflammation.
I. TESTING OF THE CRYSTALLINE POTASSIUM SALTS OF THE INVENTION
[0120] A hallmark of inflammation is the adhesion and
transmigration across endothelium of neutrophils, eosinophils and
other inflammatory cells. A similar process is observed for the
migration of cells across polarized epithelial cells that occur in
the lung, gastrointestinal tract and other organs. Cell culture
models of these processes are available and have been used to show
that lipoxin A.sub.4 and stable lipoxin A.sub.4 analogs inhibit the
transmigration of human neutrophils across human endothelial cells
and epithelial cells, including the human intestinal epithelial
cell line T.sub.84. Accordingly, one of ordinary skill in the art
can test a crystalline potassium salt of Formula (I) for its
ability to inhibit the transmigration of human neutrophils and
eosinophils across human endothelial cells and epithelial cells by
performing assays similar to those described in Colgan, S. P., et
al., J. Clin. Invest. (1993), Vol. 92, No. 1, pp. 75-82; and
Serhan, C. N., et al., Biochemistry (1995), Vol. 34, No. 44, pp.
14609-14615.
[0121] The air pouch model and/or the mouse zymosan-induced
peritonitis model may be used to evaluate the in vivo efficacy of
the crystalline potassium salt of Formula (I) in treating an
inflammatory response. These are acute experimental models of
inflammation characterized by infiltration of inflammatory cells
into a localized area. See, e.g., the in vivo assays described in
Ajuebor, M. N., et al., Immunology (1998), Vol. 95, pp. 625-630;
Gronert, K., et al., Am. J. Pathol. (2001), Vol. 158, pp. 3-9;
Pouliot, M., et al., Biochemistry (2000), Vol. 39. pp. 4761-4768;
Clish, C. B., et al., Proc. Natl. Acad. Sci. U.S.A. (1999), Vol.
96, pp. 8247-8252; and Hachicha, M., et al., J. Exp. Med. (1999),
Vol. 189, pp. 1923-30.
[0122] Animal models (i.e., in vivo assays) may also be utilized to
determine the efficacy of the crystalline potassium salt of Formula
(I) in treating asthma and related disorders of the pulmonary and
respiratory tract. See, e.g., the assays described in De Sanctis,
G. T. et al., Journal of Clinical Investigation (1999), Vol. 103,
pp. 507-515; and Campbell, E. M., et al., J. Immunol. (1998), Vol.
161, No. 12, pp. 7047-7053.
[0123] Alternatively, a crystalline potassium salt of Formula (I)
may be tested for its efficacy in the claimed methods of use by
employing the assays described in U.S. Pat. No. 6,831,186 and in
U.S. Patent Application Publication No. 2004/0162433, the pertinent
disclosures of which are incorporated in full in their entireties
herein.
J. ADMINISTRATION OF THE CRYSTALLINE POTASSIUM SALTS OF THE
INVENTION
[0124] Administration of a crystalline salt of Formula (I), as a
single stereoisomer or any mixture of stereoisomers, or as a
cyclodextrin clathrate thereof, or as a solvate or polymorph, in
pure form or in an appropriate pharmaceutical composition, can be
carried out via any of the accepted modes of administration or
agents for serving similar utilities. Thus, administration can be,
for example, orally, nasally, parenterally, pulmonary, topically,
transdermally, or rectally, in the form of solid, semi-solid,
lyophilized powder, or liquid dosage forms, such as for example,
tablets, suppositories, pills, soft elastic and hard gelatin
capsules, powders, solutions, suspensions, aerosols, patches, or
the like, preferably in unit dosage forms suitable for simple
administration of precise dosages. The compositions will include a
potassium salt of the invention as the/an active agent and a
conventional pharmaceutical carrier or excipient and, in addition,
may include other medicinal agents, pharmaceutical agents,
carriers, adjuvants, etc., as are generally known in the art.
[0125] Actual methods of preparing such dosage forms are known, or
will be apparent, to those skilled in this art; for example, see
Remington's Pharmaceutical Sciences, 18th Ed., (Mack Publishing
Company, Easton, Pa., 1990). The composition to be administered
will, in any event, contain a therapeutically effective amount of a
crystalline potassium salt of Formula (I) for treatment of a
disease-state characterized by inflammation in accordance with the
teachings of this invention.
[0126] Generally, depending on the intended mode of administration,
the pharmaceutically acceptable compositions will contain about
0.1% to about 99.9% by weight of a crystalline potassium salt of
Formula (I) and about 99.9% to about 0.1% by weight of a suitable
pharmaceutical excipient.
[0127] In one embodiment, the route of administration is oral,
using a convenient daily dosage regimen that can be adjusted
according to the degree of severity of the disease-state to be
treated. For such oral administration, a pharmaceutically
acceptable composition containing the crystalline potassium salt of
Formula (I) is formed by the incorporation of one or more of the
normally employed pharmaceutically acceptable excipient(s). Such
compositions take the form of solutions, suspensions, tablets,
pills, capsules, powders, sustained release formulations and the
like.
[0128] Preferably, such compositions will take the form of a
capsule, caplet or tablet and therefore will also generally contain
a diluent, a disintegrant, a lubricant, and a binder.
[0129] The crystalline potassium salt of Formula (I) may also be
formulated into a suppository comprising the active ingredient
disposed in a carrier that slowly dissolves within the body, such
as those normally employed in this capacity.
[0130] Liquid pharmaceutically administrable compositions can, for
example, be prepared by dissolving, dispersing, etc., a potassium
salt of the invention and optional pharmaceutically acceptable
adjuvants in a carrier, such as, for example, water, saline,
aqueous dextrose, glycerol, ethanol and the like, to thereby form a
solution or suspension.
[0131] If desired, a pharmaceutical composition of the invention
may also contain minor amounts of auxiliary substances such as
wetting or emulsifying agents, pH buffering agents, antioxidants,
and the like.
[0132] The crystalline potassium salt of Formula (I) is
administered in a therapeutically effective amount, which will vary
depending upon a variety of factors including the activity of the
specific compound employed; the metabolic stability and length of
action of the crystalline potassium salt of Formula (I); the age,
body weight, general health, sex, and diet of the patient; the mode
and time of administration; the rate of excretion; the drug
combination; the severity of the particular disease-state(s) to be
treated; and the host undergoing therapy.
EXAMPLES
[0133] The following Examples further describe the preparation of
the crystalline potassium salt of Formula (Ia). The crystalline
potassium salts of other lipoxin A.sub.4 analogs of Formula (I) may
also be prepared analogously.
Example 1
Preparation of Monohydrate Form of the Crystalline Potassium Salt
(Ia) by Crystallisation and Drying Under Conditions that Correlate
with Stability Domain of the Monohydrate
[0134]
2-((2S,3R,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrid-
eca-4,6,10-trien-8-ynyloxy)acetic acid (compound (IIa)) (964 g) was
dissolved in a mixture of dry ethanol (3.850 L) and water (0.580
L). In a second flask, potassium hydroxide pellets (172.2 g) were
dissolved in a mixture of water (0.580 L) and dry ethanol (3.850
L). The potassium hydroxide solution was added slowly to the
solution of starting acid (IIa) at 20.degree. C. until pH of 8.5
was measured using wet pH paper. Seed crystals (2.5 g) were added
to the solution. After 90 minutes at 22.degree. C., a seed bed
formed and the suspension was cooled to -10.degree. C. within 45
min and stirred at this temperature for an additional 2 hours. The
cold suspension was then filtered using a suction filter with
filter paper. The collected crystals were washed three times with
1.6 L of a cooled mixture of ethanol/water (-10.degree. C.; 6.0% wt
of water), and then dried to a constant mass at 200 mbar/30.degree.
C. in a vacuum-drying cabinet using air (relative humidity
.about.30%) as the sweep gas. The drying process was controlled by
the determination of the water content (via Karl Fischer Titration)
of several samples taken during the drying process. The crystalline
monohydrate form of the potassium salt of Formula (Ia) (901 g) was
obtained.
Example 2
Preparation of Monohydrate Form of the Crystalline Potassium Salt
(Ia) by Drying Via a Microwave Dryer
[0135]
2-((2S,3R,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrid-
eca-4,6,10-trien-8-ynyloxy)acetic acid (compound (IIa)) (50.05 g)
was dissolved in a mixture of dry ethanol (158.11 g) and water
(30.07 g). In a second flask, potassium hydroxide pellets (12.24 g)
were dissolved in a mixture of water (41.22 g) and dry ethanol
(216.15 g). The potassium hydroxide solution (180.21 g) was added
slowly to the solution of starting acid (IIa) at 20.degree. C.
until pH of 8.5 was measured using wet pH paper. The solution was
cooled down to 0.degree. C. Seed crystals were suspended in ethanol
and the resulting suspension (0.3 g) was added to the solution.
After 30 min a seed bed formed and the suspension was cooled to
-12.degree. C. within 30 min and stirred at this temperature for an
additional 1 hour. The cold suspension was then filtered using a
suction filter with filter paper. The collected crystals were
washed with 0.1 L of a cooled mixture of ethanol/water (-12.degree.
C.; 4.0% wt of water). A sample of the wet filterpad showed the
dihydrate via using XRPD analysis. Then the drying process was
started in a microwave dryer. Drying conditions: Power=80W,
pressure inside the dryer <150 mbar. After 3.7 hours drying time
the mass of the crystals was constant and the crystalline
monohydrate form of the potassium salt of Formula (Ia)
(XRPD-Analysis, thermogravimetric analysis) (38.97 g) was
obtained.
Example 3
Preparation of Dihydrate Form of the Crystalline Potassium Salt
(Ia) by Crystallization and Drying Under Conditions that Correlate
with the Stability Domain of the Dihydrate
[0136]
2-((2S,3R,4E,6E,10E,12S)-13-(4-fluorophenoxy)-2,3,12-trihydroxytrid-
eca-4,6,10-trien-8-ynyloxy)acetic acid (compound (IIa)) (500 mg)
was dissolved in ethanol (2 mL). Water (0.75 mL) was added to the
solution. The resulting clear solution was stirred. Potassium
hydroxide pellets (85.3 mg) were dissolved in ethanol (2.84 mL).
The resulting solution was clear and without a solid phase. An
equimolar amount of the clear potassium hydroxide solution was
added to the solution of starting acid (IIa). The dosage of the
potassium hydroxide solution added was carried out by a pH check
(wet pH-indicator strip). The addition of the potassium hydroxide
solution was stopped when the solution reached a pH of 8.5. The
stirred solution was cooled to -10.degree. C. After 2 hours, a
suspension was detectable. The suspension was stirred an additional
hour. The suspension was centrifuged in a precooled centrifuge and
the mother liquid was decanted. The solid phase was dried in a
circulating air dryer at 30.degree. C. The atmosphere of the
circulating air dryer was conditioned to 70% relative humidity by
sweep gas humidification. A sweep gas flow (N.sub.2) was
continuously introduced into the dryer. The sweep gas flow was
alternately dry or moistened with water. The time periods of the
moistened versus the dry N.sub.2 flow were regulated via automatic
control technology that considers the relative humidity inside the
dryer. Using this technique, it was possible to guarantee a
relative humidity of 70% inside the dryer during the storage
period. The XRPD analysis of the wet filterpad as well as samples
of the solid in the dryer after 8 hours and 32 hours (=dry product)
drying time showed the crystalline dihydrate form of the potassium
salt (Ia).
Example 4
Preparation of Dihydrate Form of the Crystalline Potassium Salt
(Ia) from the Monohydrate Form by Storage Under Dihydrate
Conditions
[0137] The monohydrate form of the potassium salt (Ia) (1.697 g)
was transferred into a dish. The monohydrate form of the substance
at the beginning of the process was established by XRPD-analysis
and thermogravimetric analysis. The mass of the sample taken was
127 mg. The dish was transferred into a circulating air dryer. The
storage conditions were atmospheric pressure and 25.degree. C. A
moistened sweep gas flow (N.sub.2) analogous to Example 2 was
continuously introduced into the dryer. Using this technique, it
was possible to guarantee a relative humidity of 70% inside the
dryer during the storage period. The first sample (mass=239 mg) was
taken after about 48 hours and represented the dihydrate form of
the potassium salt (Ia) (XRPD analysis, thermogravimetric
analysis). The second sample (mass=220 mg) was taken another 24
hours later. This sample of the stored substance also represented
the dihydrate form (XRPD-Analysis, thermogravimetric analysis). The
remaining mass inside the dish=1.168 g of the crystalline dihydrate
form of the potassium salt (Ia).
Example 5
Preparation of Anhydrate Form of the Crystalline Potassium Salt
(Ia) from the Monohydrate Form by Suspending in a Suitable
Solvent
[0138] The monohydrate form of the potassium salt (Ia) (12.42 g)
was transferred into a flask. The monohydrate form of the substance
was established by XRPD-analysis and thermogravimetric analysis.
1,4-Dioxane solvent (125 mL) were added to the flask, which was
then closed by a flexible membrane. The suspension was agitated via
a magnetic stirrer and heated up to 95.degree. C. for 6 hours,
after which the suspension was cooled down to approximately room
temperature and the crystals were isolated from solution with a
suction filter. The wet filtercake was washed with 50 mL solvent
(1,4-dioxane, room temperature) and then dried in a vacuum-drying
cabinet at 100 mbar and 40.degree. C. After 44 hours drying time,
10.851 g of the crystalline anhydrate form of the potassium salt
(Ia) (XRPD-Analysis, thermogravimetric analysis, residual solvent)
was yielded.
[0139] While the present invention has been described with
reference to the specific embodiments thereof, it should be
understood by those skilled in the art that various changes may be
made and equivalents may be substituted without departing from the
true spirit and scope of the invention. In addition, many
modifications may be made to adapt a particular situation,
material, composition of matter, process, process step or steps, to
the objective, spirit and scope of the present invention. All such
modifications are intended to be within the scope of the claims
appended hereto.
* * * * *
References